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Auteur (up) Alfonso, S.; Gesto, M.; Sadoul, B.
Titre Temperature increase and its effects on fish stress physiology in the context of global warming Type Article scientifique
Année 2020 Publication Revue Abrégée J. Fish Biol.
Volume Numéro Pages
Mots-Clés acclimation temperature; adaptive capacity; antarctic fish; atlantic salmon; climate-change; coping; cortisol; european sea bass; fresh-water; heat; heat-shock proteins; plasticity; rainbow-trout; teleost; thermal-stress; water temperature
Résumé The capacity of fishes to cope with environmental variation is considered to be a main determinant of their fitness and is partly determined by their stress physiology. By 2100, global ocean temperature is expected to rise by 1-4 degrees C, with potential consequences for stress physiology. Global warming is affecting animal populations worldwide through chronic temperature increases and an increase in the frequency of extreme heatwave events. As ectotherms, fishes are expected to be particularly vulnerable to global warming. Although little information is available about the effects of global warming on stress physiology in nature, multiple studies describe the consequences of temperature increases on stress physiology in controlled laboratory conditions, providing insight into what can be expected in the wild. Chronic temperature increase constitutes a physiological load that can alter the ability of fishes to cope with additional stressors, which might compromise their fitness. In addition, rapid temperature increases are known to induce acute stress responses in fishes and might be of ecological relevance in particular situations. This review summarizes knowledge about effects of temperature increases on the stress physiology of fishes and discusses these in the context of global warming.
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ISSN 0022-1112 ISBN Médium
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Notes WOS:000588735000001 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2920
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Auteur (up) Alfonso, S.; Sadoul, B.; Cousin, X.; Begout, M.-L.
Titre Spatial distribution and activity patterns as welfare indicators in response to water quality changes in European sea bass, Dicentrarchus labrax Type Article scientifique
Année 2020 Publication Revue Abrégée Appl. Anim. Behav. Sci.
Volume 226 Numéro Pages Unsp-104974
Mots-Clés ammonia toxicity; atlantic salmon; avoidance-behavior; behavioral-responses; Behaviour; current issues; Fish; hyperoxia; hypoxia tolerance; marine fish; rainbow-trout; Stress; stress-response; Water quality; Welfare
Résumé In aquaculture, fish are exposed to unavoidable stressors that can be detrimental for their health and welfare. However, welfare in farmed fish can be difficult to assess, and, so far, no standardized test has been universally accepted as a welfare indicator. This work contributes to the establishment of behavioural welfare indicators in a marine teleost in response to different water quality acute stressors. Groups of ten fish were exposed to high Total Ammonia Nitrogen concentration (High TAN, 18 mg.L-1), Hyperoxia (200 % O-2 saturation), Hypoxia (20 % O-2 saturation), or control water quality (100% O-2 saturation and TAN < 2.5 mg.L-1) over 1 hour. Fish were then transferred in a novel environment for a group behaviour test under the same water quality conditions over 2 hours. Videos were recorded to assess thigmotaxis, activity and group cohesion. After this challenge, plasma cortisol concentration was measured in a subsample, while individual behavioural response was measured in the other fish using novel tank diving test. Prior to this study, the novel tank diving test was validated as a behavioural challenge indicative of anxiety state, by using nicotine as anxiolytic drug. Overall, all stress conditions induced a decrease in activity and thigmotaxis and changes in group cohesion while only fish exposed to Hypoxia and High TAN conditions displayed elevated plasma cortisol concentrations. In post-stress condition, activity was still affected but normal behaviour was recovered within the 25 minutes of the test duration. Our work suggests that the activity, thigmotaxis and group cohesion are good behavioural indicators of exposure to degraded water quality, and could be used as standardized measures to assess fish welfare.
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ISSN 0168-1591 ISBN Médium
Région Expédition Conférence
Notes WOS:000531095400002 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2794
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Auteur (up) Boukef, I.; El Bour, M.; Al Gallas, N.; El Bahri, O.; Mejri, S.; Mraouna, R.; Ben Aissa, R.; Boudabous, A.; Got, P.; Troussellier, M.
Titre Survival of Escherichia coli Strains in Mediterranean Brackish Water in the Bizerte Lagoon in Northern Tunisia Type Article scientifique
Année 2010 Publication Revue Abrégée Water Environ Res
Volume 82 Numéro 11 Pages 2249-2257
Mots-Clés bizerte lagoon; brackish water; coastal waters; cytotoxicity; enteric bacteria; escherichia coli; fecal-coliforms; marine waters; salmonella-typhimurium; seawater microcosms; sewage; shigella-dysenteriae type-1; sunlight; survival; viability; virulence
Résumé This study investigated survival and virulence of Escherichia coli strains exposed to natural conditions in brackish water. Two E. coli strains (O126:B16 and O55:B5) were incubated in water microcosms in the Bizerte lagoon in Northern Tunisia and exposed for 12 days to natural sunlight in June (231 to 386 W/m(2), 26 +/- 1 degrees C, 30 g/L) and in April (227 to 330 W/m(2), 17 +/- 1 degrees C, 27 g/L) or maintained in darkness for 21 days (17 +/- 1 degrees C, 27 g/L). The results revealed that sunlight was the most significant inactivating factor (decrease of 3 Ulog within 48 hours for the two strains) compared to salinity and temperature (in darkness). Survival time of the strains was prolonged as they were maintained in darkness. Local strain (E. coli O55:B5) showed better survival capacity (T(90) = 52 hours) than E. coli O126:B16 (T(90) = 11 h). For both, modifications were noted only for some metabolic activities of carbohydrates hydrolysis. Cytotoxicity of the two strains, tested on Vero cell, was maintained during the period of survival. Water Environ. Res., 82, 2249 (2010).
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Volume de collection Numéro de collection Edition
ISSN 1061-4303 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 864
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Auteur (up) de Verdal, H.; Mekkawy, W.; Lind, C.E.; Vandeputte, M.; Chatain, B.; Benzie, J.A.H.
Titre Measuring individual feed efficiency and its correlations with performance traits in Nile tilapia, Oreochromis niloticus Type Article scientifique
Année 2017 Publication Revue Abrégée Aquaculture
Volume 468 Numéro Pages 489-495
Mots-Clés bream sparus-aurata; compensatory growth; conversion efficiency; diet environments; Feed conversion ratio; Feed efficiency; Feed intake; fish-meal; food; genetic-improvement; growth; Nile tilapia; rainbow-trout; Repeatability; salmon salmo-salar; selection; Sex
Résumé Estimating individual feed intake of fish held in groups has long been a challenge precluding precise knowledge of the individual variation of feed efficiency (FE) in fish. In this study, counts of the number of feed pellets (1.63 mg on average) eaten by individual tilapia (Oreochromis niloticus) held in 8 mixed sex groups of 15 fish were measured from video recordings made over a period of 10 days where fish were fed twice daily to achieve compensatory growth after 10 days of fasting. The initial body weight of the fish was 9.77 +/- 2.03 g. Accumulated measures of feed intake (FI) over 11 meals were found to achieve 95% repeatability and a high accuracy of estimation of FI. During the FI measurement period, the average fish growth was 12.0 +/- 3.6 g, feed intake was 0.99 g day (-1), and feed conversion ratio (FCR) was 0.86 +/- 0.20. FI differences accounted for 56% of the observed individual growth variations, and 44% was related to individual variations of FE. On average males grew 24.2% faster than females but consumed 12.1% more feed. Males showed an 11.7% better FCR than females, whereas residual feed intake (RFI) differences were not significant between sexes. FCR and RFI were moderately and significantly correlated (0.58 +/- 0.06) but FCR and FI, and body weight gain (BWG) and RFI, were not, highlighting the complex relationships between feed efficiency traits. The approach described here demonstrates a means to accurately investigate FE traits in fish and to assess the potential for their genetic improvement. Statement of relevance: Feed efficiency has strong economic and environmental impact. (C) 2016 Elsevier B.V. All rights reserved.
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Volume de collection Numéro de collection Edition
ISSN 0044-8486 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1713
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Auteur (up) de Verdal, H.; O'Connell, C.M.; Mekkawy, W.; Vandeputte, M.; Chatain, B.; Begout, M.-L.; Benzie, J.A.H.
Titre Agonistic behaviour and feed efficiency in juvenile Nile tilapia Oreochromis niloticus Type Article scientifique
Année 2019 Publication Revue Abrégée Aquaculture
Volume 505 Numéro Pages 271-279
Mots-Clés Agonstic behaviour; arctic charr; atlantic salmon; brain serotonergic activity; brown trout; conversion ratio; Correlation; dominance relationships; Feed efficiency; food acquisition; genetic-improvement; Nile tilapia; Performances; salvelinus-alpinus; social-status
Résumé Given the strong effects of behavioural hierarchies on growth in many cultured species and the key role of feed efficiency in aquaculture economics, understanding the nature of the interaction of these variables is important for the sustainability of aquaculture. The relationship between agonistic behaviour, growth and feed efficiency in Nile tilapia, Oreochromis niloticus, was studied by rearing 120 fish in eight aquaria. Fish were video-recorded to estimate the occurrence of agonistic behaviour during a fasting and a refeeding period. Growth, feed intake and feed conversion efficiency (FCE – calculated as the inverse of feed conversion ratio (FCR)) were subsequently measured individually for each fish. Fish showed 58% less agonistic traits during the fasting period compared to the feeding period, but generally, an aggressive fish during the fasting period was also aggressive during the refeeding period. The nature of agonistic behaviours between individuals was used to assess the presence of hierarchical relationships between fish. There were dominance hierarchies established in each experimental aquarium that despite minor shifts were maintained throughout the experiment. Agonistic behaviours were strongly correlated with each other, the aggression Index (AI) and with hierarchy rank. PCA analysis of the agonistic behaviours summarising the behavioural information showed little or no correlation between agonistic behaviour, fish growth or FCE. FCE was correlated with body weight gain (BWG). These results suggest that agonistic interactions in juvenile Nile tilapia do not have a large impact on growth and feed conversion efficiency.
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Editeur Lieu de Publication Éditeur
Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0044-8486 ISBN Médium
Région Expédition Conférence
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2583
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